摘要
目的探讨螺旋CT增强多期扫描对实验性闭袢性肠梗阻肠壁缺血的诊断价值.方法新西兰大白兔24只,分为3组,每组8只;取10～15 cm长小肠结扎两端成闭袢,同时结扎闭袢肠段的引流静脉;于模型制成后0.5 h(A组)、1～2 h(B组)和3～5 h(C组)行螺旋CT多期扫描.采用盲法对比分析CT表现与肠壁组织病理改变的关系.结果 A组 7只及B组 4只兔闭袢肠壁增强扫描出现持续强化,C组8只的闭袢肠壁均无明显持续强化.CT值测量:在增强前、增强后的动脉期、静脉期和延迟期A组闭胖肠壁的CT值分别为 (56.3±4.3)HU,(139.5±17.9)HU,(145.1±12.6)HU和 (124.9±10.5)HU;B组分别为 (58.8±5.6)HU,(82.5±13.7)HU,(101.0±20.3)HU和 (95.0±16.4)HU;C组分别为 (62.1±7.8)HU,(63.9±6.6)HU,(59.5±4.40)HU和 (59.6±6.9) HU.在平扫时,A组、B组、C组闭袢肠壁之间的CT值差异无统计学意义(P>0.05).在增强后的同一时期内,无论是在动脉期、静脉期或是延迟期,A组闭袢肠壁的CT值最大,B组次之,C组最小,而且差意有统计学意义(P<0.05).在平扫、增强后各期内,A组、B组和C组对照肠袢的CT值差异无统计学意义(P>0.05).与病理组织学对照,肠壁无坏死组出现持续强化征象的发生率(11/13)明显高于肠壁坏死组 (1/11)(P<0.05).结论螺旋CT多期增强扫描可评价肠壁不同时间的缺血,持续强化主要见于肠壁缺血的早期阶段,而已坏死的肠壁在增强各期均无强化.
Objective To evaluate the bowel ischemia in experimental closed loop obstruction by using multi-phase spiral CT. Methods Twenty-four New Zealand rabbits of both sexes (mean age, 4 months, and mean body weight, 2.5-3.0 kg) were divided randomly into three groups with each group containing 8 rabbits. After clamping 10—15 cm segments of small bowel and their veins for 0.5 hours (Group A), 1—2 hours (Group B), and 3—5 hours (Group C), respectively, multi-phase spiral CT was performed at baseline, and at arterial, venous, and delayed phases after intravenous contrast administration. Then the rabbits were sacrificed to observe their surgical and histological changes. Two radiologists, blinded to the animal model classification and their histological results, individually reviewed the CT images to observe the CT appearances of the closed loop. Statistical significance criteria was determined by P<0.05. Results Continuous enhancement at all phases of the closed loop bowel wall was seen in 7 rabbits of group A, 4 rabbits of group B, and zero of group C, respectively. The CT attenuation of the closed loop wall at baseline and, at arterial, venous, and delayed phases were (56.3±4.3) HU, (139.5±17.9) HU, (145.1±12.6) HU, and (124.9±10.5) HU in group A, (58.8±5.6) HU, (82.5±13.7) HU, (101.0±20.3) HU, and (95.0±16.4) HU in group B, and (62.1±7.8) HU, (63.9±6.6) HU, (59.5±4.4) HU, and (59.6±6.9) HU in group C, respectively. The closed loop CT attenuations among the three groups were not significantly different (P>0.05) at baseline, however, they were significantly different (P<0.05) at all phases after enhancement. Among rabbits without necrotic closed loop, 11 of 13 had continuous enhancement at all phases, while only 1 of 11 rabbits with necrotic closed loop showed continuous enhancement (P<0.05). Conclusion The ischemia of bowel wall in different phases after clamping small bowel and their veins can be evaluated by using enhanced multi-phase spiral CT. Continuous enhancement of bowel wall in multi-phase spiral CT can be seen prominently in the early bowel ischemia, but necrotic bowel shows no enhancement.
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2005年第7期755-760,共6页
Chinese Journal of Radiology
